To whom was it sold? Any reference for that?

I still thought it was some single persons product.

Update; ah ok sold to two people, not some huge company - https://enclose.horse/about-us:

---- Our Story

Enclose.horse was originally created by Shivers as an interesting optimization problem, the kind of thing you'd find in a Leetcode challenge or an Advent of Code puzzle. But after prototyping it, it turned out to be genuinely fun to play, and it grew into a fully-fledged game.

Today, enclose.horse is developed and maintained by Ryan and Praveen. We're constantly adding new features, puzzle mechanics, and quality-of-life improvements based on community feedback. If you have ideas, we'd love to hear them!